Air volume control



W` E. KENT Aug. 24, 1943.

AIR VOLUME CONTROL Filed March l2, 1942 l @a ,0, 0 u f 5 d fm J Z /M JEZm W E w y v V D M M w w A@ M Mw@ 7 U im un inlihnl Patented Aug. 24,1943 UNITED STATES PATENT oFFicE AIR VOLUME CONTROL Walter E. Kent,Decatur, lll; Application March 12, 1942, Serial No. 434,409

20 Claims.

My invention relates to automatic controls for self-contained watersystems of the type in which distribution is eiected by pressureestablished in the storage tank, as distinguished from gravity nowsystems.4 Arrangements of this character are vcustomarily used incountry districts or in other locations which do not have access tocentral pumping stations.

Cardinal requirements of such a system are an automatic introduction ofair into the storage tank and the maintaining of this air above apredetermined pressure over the surface of the water to insure adequateiiow at the various outlets of the system. Failure to introduce air inproper amounts results in water logged tanks, sluggish distribution inthe system, increased wear of the motor and pump, and higher operatingcosts. One objection to existing systems is that the air is forced intothe tank at or near the shut-o pressure which is ordinarily of the orderof forty pounds per square inch.

It is therefore one object of my invention to devise a fully automaticair control for introducing air into the storage tank at the allowableminimum tank pressure or a pressure close thereto, i. e., when the pumpis operating at full capacity and highest emciency.

A further object is to provide a control which automatically interruptsthe flow of air into the tank at a pressure materially less than theshutoil pressure of the pump.

These and further objects of my invention will be set forth in thefollowing specification, reference being had to the accompanyingdrawing, and the novel means by which said objects are eiectuated willbe definitely pointed out in the claims.

In the drawing:

Fig. 1 is an elevation showing a characteristic water system equippedwith my-automatic air control device.

Fig. 2 is a sectional elevation of shown in Fig. 1.

Figs. 3, 4 and 5 are similar elevations showing various modications.

Referring to Figs. 1 and 2 of the drawing, the numeral Ill designates apressure tank which supplies water to any desired number of ou letsthrough a pipe Il and to whichvwater is delivered through a pipe I2 bymeans of a pump I3 connected to a suction pipe It that may extend intoawell. The pipe Iii may include a check valve I5 arid the pump I3 may beof any standard type provided that it is capable of pumping some air.The pump is driven by a the control motor I6 under the control of apressure switch IJ, as commonly used in systems of this character, whichis electrically connected to the motor and to an electrical supply by acircuit I8.

'I'he switch I1 is responsive to the pressure in the pipe I2 and Whileit may be adjusted to stop and start the motor at any desired pressurelimits, it will be considered for purpose of example and not by way oflimitation that the motor will start when the Ipressure in the tankfalls to twenty pounds `per square inch and will stop when the pressurein the tank reaches forty pounds per square inch. Water levels in thetank corresponding to these pressures, respectively, and with a normalair supply in the tank, are indicated by the numerals I9 and 2li in Fig.1.

The control for automatically introducing air into the tank isdesignated by the numeral 2| in Fig. 1 and is shown in section in Fig. 2to which reference will now be made. The control comprises abuttingcasing parts 22 and 23 between which are clamped a diaphragm 24 and a'stiff plate 25 which defines with the casing part 22 a suction chamber26. This chamber communicates through a port- 21 with a pipe 28 which isconnected to the suction pipe I4.

An air inlet nipple 29 is provided to permit under certain conditionsthe entrance of atmospheric air into the chamber 26 and its inlet endincludes a passage 30 that is closed by a ball V valve 3l under theimpulse of a light spring 32,

except when a partial vacuum is created in the chamber 26 as hereinafterdescribed.

A valve 33 provided with guide ribs 33 is disposed in operative relationto the port 21 and is carried by one end of a stem 34 whose opposite endextends freely through the plate 25 for securement to the diaphragm 24.A spring 35 encircles the stem 34 with its opposite ends abutting thecasing part 22 and diaphragm 24, respectively, and acts to maintain thevalve 33 in the open position and the diaphragm in the bowed position asshown. The free portion of the diaphragm includes an aperture 36 whichmay be of any desired size, depending upon the conditions of operation,but which in any case provides a restricted means of communicationbetween the chamber 26 and a chamber 3l in the casing part 23., Underthe specic conditions assumed hereii'r, the diameter of the aperture maybe of the order of 3/64". The chamber 31 connects through a pipe 38 withthe tank preferably at the low pressure water level I9 and Pump throughthe pipe I4 and delivering it to the tank by way of the pipe I2. Thepump establishes a ture 36 by the plate 25.

a pressure gage 39 may be mounted on the part 23 to indicate tankpressures.

In describing the operation of my improved control and system, it willbe assumed that the pump I3 is not running. The pressures in thechambers 2,6 and 31 are then equalized so that the valve 33 is held openby the spring and the diaphragm occupies the bowed position shown inFig. 2, i. e., the aperture 36 is not masked by the plate Z5. g

When the tank pressure falls to twenty pounds, the pressure switch I1closes and the I3 begins operating, drawing water partial vacuum in thechamber 26 which tends to unseat the valve 3l and permit a ilow ofatmospheric air into the system, but whether this condition resultsdepends upon the location of the water level in the tank when the pumpstarts. If this level is substantially as indicated by the numeral I9,i. e., below the aperture 36, no partial vacuum will be created in thechamber 26, because air iiowing through the aperture will break thesuction in the chamber 26 and will be recirculated by the pump back tothe tank. The

ball 3I remains seated during this period.

However, if the water level in the tank is above the aperture 36 whenthe pump starts, the ow of water through the aperture from the tank isinsuilicient by reason of its restricted area to destroy the partialvacuum in the chamber 26, so that the valve 3| is pulled open and air isdrawn into the system from the atmosphere.

The loading applied by the spring to the diaphragm is preferably suchthat when a tank pressure of twenty-three or twenty-four pounds isreached, the diaphragm 24 is iiexed to the left to close the valve 33and to also mask the aper- This action occurs in either of the above twomodes of operation and the valve 33 remains closed until the pump isstopped by the establishment of the high pressure limit in the tank.When the pump stops, the pressure in the control equalizes on both sidesof the diaphragm, whereupon the spring 35 opens the valve 33 inpreparation for the next cycle.

It will be particularly noted that the air is introduced into the systemwithin a tank pressure range of twenty to twenty-four pounds, orgenerally at a pressure substantially closer to the low tank pressurethan to the high, that is, during the period when the pump is operatingat the fullest capacity and highest efficiency. Such an arrangement`contrasts advantageously with other types of systems in which the airis introduced at or near the high pressure limit.

In Fig. 3 is illustrated a modification of the control wherein thediaphragm is eliminated in favor of a stiff plate 40 which is clampedbetween the casing parts 22 and 23 and includes an aperture 4Icorresponding in size and function to the aperture 36. As before, thevalve 33 is operably related to the port 21 and is mounted on one end ofa stem 42 whose opposite end extends slidably a spring 44 whose oppositeends abut, respectively,

an interior wall of the casing part 22 and a washer 45 xed to the stem42. Otherwise, this form of the control is identical with thatillustrated in Fig. 2 and its operation is similar in that, when the-pump is started, the creation of a partial vacuum in the chamber 26depends upon the relation of the water level in the tank to4 theaperture 4I. Above a tank pressure of twenty-three or twenty-Q fourpounds, the head 43 is moved towards the left to close the valve 33 andmask the aperture 4I, the spring' 44 being sized in relation to the areaof the head 43 to accomplish this result. When the pump stops, pressureis equalized in the chambers 26 and 31 whereupon the valve 33 and headare moved to the open positions shown by the spring 44.

The modification shown in Fig. 4 is in many respects the mostpreferable. This structure utilizes a diaphragm 46 to which is securedone end of a valve stem 41 whose opposite end carries the usual valve 33for controlling ilow through the port 21. As in the other forms, thevalve 33 is biased to an open position by a spring 48 whose ends abutthe casing part 22 and the diaphragm 46. An aperture 49, correspondingin size and function to the previously noted apertures, is provided inthe stem 41 to establish a restricted means of communication between thechambers 26 and 31. The operation of this device is the same as thatillustrated in Fig. 2, the diierence being that the aperture 49 isalways o pen. In this form, the aperture 49 could be located in thediaphragm, if desired.

In Fig. 5 which shows only a portion of a still further modification,the arrangement and operation is identical with the form shown in Fig.4, except that an aperture is not provided in either the diaphragm 50 orthe valve stem 5I. Hence, there is no direct communication between thechambers 26 and 31 and it would be necessary to use a relief valve (notshown) with the tank to periodically discharge excess air.

I claim:

1. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling iiow through the port, and a movablemember connected to the valve and responsive to a predetermined tankpressure for closing the valve.

2. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a -valve for controlling ow through the port, a movable memberconnected to the valve and responsive to a predetermined tank pressurefor closing the valve, and spring means interposed between the casingand member and operative to hold the valve open below said pressure.

3. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openWhen a suction is established in the chamber and closed at al1 othertimes, a valve for controlling flow through the port, a diaphragmconnected to the valve and exposed on one side to the tank pressure andon the opposite side to the suction pressure, and spring meansinterposed between the casing and diaphragm and operative to hold thevalve open below a predetermined tank pressure and yielding to 'permitthe closing of the valve by the diaphragm at said pressure.

ber and closed at all other times, a valve forI controlling ow throughthe port, and a movable member connected to the valve having an apertureproviding a restricted means of communication between the suctionchamber and tank and responsive to a predetermined tank pressure forclosing the valve.

5. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established ln the chamber and closed at all othertimes, a valve for controlling flow through the port, and a movablemember connected to the valve having an aperture providing a restrictedmeans of communiproviding a restricted means of communication betweenthe suction chamber and tank, the aper- Y ture being sized to admitliquid from the tank'in a quantity insuilicient to destroy the suctionin the suction chamber when the liquid in the tank is at an elevationabove the aperture and airfrom the tank to break the suction when theliquid in the tank is at the same elevation as or below the aperture,spring means interposed between the casing andv diaphragm and operativeto holdthe valve open below a predetermined tank pressure and yieldingto permit the closing of the valve by the diaphragm at said pressure,and closure means overlying the aperture when the diaphragm is`-fiexedto close the valve.

8. In a liquid pressure system, the combination of a tank, a pump forsupplying liquid under pressure to the tank, means for starting andstopping the pump at predetermined minimum and maximum tank pressures,respectively, a suction chamber having an outlet port communieating withthe pump and an air inlet, the inlet being open when a suction isestablished inv the chamber and closed at all other times, a valve forcontrolling i'low through the port, a passage including a restrictedportionv connecting the chamber with the tank substantially atvthe lowpressure liquid level, the portion being sized to admit liquid from thetank in a quantity insu-fcation between the suction chamber and tank andresponsive to a predetermined tank pressure for closing the valve, theaperture being sized to admit liquid from the tank in a quantityinsuflcient to destroy the suction in the suction chamber when theliquid in the tank is at an-elevation abovethe aperture and air from thetank to relieve the suction when the liquid in the tank is at the sameelevation as or below the aperture.

6. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying' liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pumpand an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling ilow through the port, a. diaphragmconnected -to the valve and having an aperture providing a restrictedmeans of communication between the suction chamber and tank, theaperture being sized to admit liquidfrom the tank in a quantityinsufficient to destroy the suction in the suction chamber when theliquid in the tank is at an elevation above the aperture and air fromthe tank to relieve the suction when the liquid in the tank is at thesame elevation as or below the aperture, and spring means interposedbetween the casing and diaphragm and operative to hold the valve openbelow a predetermined tank pressure and yielding to permit the closingof the valve by the diaphragm at said pressure.

7. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling ow through the port, a diaphragmconnected to the valve and having an aperture flcient to destroy thesuction in the suction chamber When the liquid in the tank is at anelevation above the portion and air from the tank to break the suctionwhen the liquid in the tank is at the same elevation as or below theportion, and means including the valve responsive to a tank pressuresubstantially less than the maximum tank pressure for interrupting theair supply.

9. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling flow through the port, a wall portionseparating the chamber from a passage communicating with the tank, amovable member exposed to the tank pressure in the passage and connectedto the valve, and springmeans abutting the casing and connected to thevalve, the spring means being operative to hold the valve open below apredetermined tank pressure and yielding to permit the closing of thevalve by the member at said pressure.

10-. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling ow through the port, a wall portionseparating the chamber from a passage communicating with the tank andhaving an aperture providing a restricted means of communibelow theaperture, a movable member extending through the wall portion forexposure to the tank pressure in the passage and connected to the valve,and spring means abutting the casing and connected to the valve, thespring means being operative to hold the valve open below apredetermined tank pressure and yielding to permit the closing of thevalve by the member at said pressure.

11. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling flow through the port, a passageincluding a portion providing a restricted means of communicationbetween the suction chamber and tank, and means connected to the valveand responsive to a predetermined tank pressure for closing the valve.

12. An air volume control for a liquid system having a tank for storingthe liquid under pressureand a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling flow through the port, a passageincluding a portion providing a restricted means of communicationbetween the suction chamber and tank, theportion being sized to admitliquid from the tank in a quantity insufficient to destroy the suctionin the chamber when the liquid in the tank is at an elevation above theportion and air from the tank to relieve the suction when the liquid inthe tank is at the same elevation as or below the portion, and meansconnected to the valve and responsive to a predetermined tank pressurefor closing the valve.

13. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying lliquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling ow through the port, a diaphragmconnected to the valve, a passage including a portion providing arestricted means of communication between the chamber and tank, theportion being sized to admit liquid from the tank in a quantityinsumcient to destroy the suction in the chamber when the liquid in thetank is at an elevation above the portion and air from the tank torelieve the suction when the liquid in the tank is at the same elevationas or below the portion, and spring means interposed between the casingand diaphragm and operative to hold the valve open below a predeterminedtank pressure and yielding to permit the closing of the valve by thediaphragm at said pressure.

14. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with Aa suction chamber having an outletport communicating 'with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling ilow through the port, a passageincluding a portion providing a restricted means of communicationbetween the chamber and tank, the portion being sized to adm-lt liquidfrom the tank in a quantity insumcient to destroy the suction in thechamber when the liquid in the tank is at an elevation above the portionand air from the tank to break the suction when the liquid in the tankis at the same elevation as or below the portion, spring meansinterposed be tween the casing and valve and operative to hold the valveopen below a predetermined tank pressure andv yielding to permit theclosing o! the valve at said pressure, and closure means connected tothe valve and exposed to the tank pressure and adapted to overlie theportion when the valve is closed.

l5. An air volume control for a liquid system f having a tank forstoring the 'liquid under pressure and a pump for supplying liquid tothe tank comprising a casing provided with a suction chamber having anoutlet port communicating with the pump and air inlet, the inlet beingopen when a suction is established in the chamber and closed at allother times, a valve for controlling flow through the port, and amovable member connected to the valve and responsive to a predeterminedtank pressure for closing the valve, the member being biased to aposition opening the valve below said pressure.

16. An air volume control for a liquid system having a tank for'storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for ccntrolling flow through the port, and a diaphragmconnected to the valve and exposed on one side to the tank pressure andon the opposite side to the suction pressure, the diaphragm closing thevalve at a predetermined tank pressure and biased .to a position openingthe valve below said pressure.

17. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet. the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling iiow through the port, and a diaphragmconnected to the valve and having an aperture providing a restrictedmeans of communication between the chamber and tank, the aperture beingsized to admit liquid from the tank in a quantity insuiilcient todestroy the suction in the chamber when the liquid in the tank is at anelevation above the aperture and air from the tank to relieve thesuction when the liquid in the tank is at the same elevation as or belowthe aperture, the diaphragm closing the valve at a predetermined tankpressure and biased to a position opening the valve below said pressure18. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a valve for controlling flow through the port, a diaphragmconnected to the valve and having an aperture means overlying theaperture when theV diaphragm is flexed to close the valve'.

19. An air volume control for a liquid system having a tank for storingthe liquid under pressure and a pump for supplying liquid to the tankcomprising a `casing provided with a suction chamber having an outletport communicating with the pump and an air inlet, the inlet being openwhen a suction is established in the chamber and closed at all othertimes, a Valve for controlling ow through the port, a Wall portionseparating the chamber from a passage communicating with the tank, and amovable member exposed to the tank pressure and connected to the valve,the member closing the valve at a predetermined tank pressure and biasedto a position opening the valve below said pressur chamber having anoutlet port communicating with the pump and an air inlet, the inletbeing open when a suction is established in the chamber and closed atall other times, a valve for controlling iiow through the port, a wallportion separating the chamber from a passage communicating with thetank and having an aperture providing a restricted means ofcommunication betweenthe chamber and passage, the aperture being sizedto admit liquid from the tank in a quantity insuiiicient to destroy thesuction in the chamber when vthe liquid in the tank is at an elevationabove the aperture and air from the tank to relieve the suction when theliquid in the tank is at the same elevation as or below the aperture,and a movable member extending through the wall portion for exposure tothe tank pressure and connected to the valve, the member closing thevalve at a predetermined tank pressure and biased to a position openingthe valve below said pressure.

WALTER E. KENT.

